News coverage of the latest issue of ISIS' English-language magazine, Dabiq, has focused on the San Bernardino and Paris attacks and Jihadi John's death, but little attention has been paid to the most pertinent issue: the Sunni-Shia divide.

ISIS' attitude towards Shia Muslims is nothing new, but the magazine's focus on these sectarian divisions, amid already heightened hostilities after Saudi Arabia's execution of a Shia cleric last month, shows how the group explains modern geopolitics through a particular historical lens.

Dabiq's cover features a Shia procession with the title "The Rafidah," a derogatory term used by Salafi-jihadi groups. In an 'expose,' ISIS presents its version of the 'truth' about Shia Islam. The 'expose,' titled "From Ibn Saba' to the Dajjal," cites lengthy opinions from Abu Musab al-Zarqawi, the al-Qaeda ideologue credited with turning the Iraqi insurgency against US forces into a sectarian conflict. Zarqawi famously declared "all-out war" against Iraqi Shia. His manhaj, or method, is lauded and referred to as "cleansing" Iraq of its Shia population.

Shia Islam is presented as rejecting and insulting the Rashidun – the righteously-guided first caliphs – and the companions of the Prophet Mohammed, as well as his wife Aisha. These figures are key to broader Sunni thought, but the entire ideological framework of Salafi-based groups is built on their conduct and sayings. An affront to them is presented as an affront to all Sunni Muslims.

Shia Islam is presented as a rejection of Islamic tradition.

Both al-Qaeda and the Taliban hold contemptuous views of Shia and have carried out acts of violence against them, but ISIS considers their stances too lenient. It scorns al-Qaeda leader Ayman al-Zawahiri's instructions to avoid targeting the mosques, business, and homes of Shia Muslim. It also rejects his description of ordinary Shia as Muslims who are ignorant about their religion and should therefore not be targeted. ISIS' own position on the targeting of Shia is clearly laid out in Dabiq as the group calls for no exceptions, for the killing of both "leaders and laymen."

As with its criticism of other jihadi groups, ISIS uses alleged openness towards Shia as a means to attack Saudi Arabia, suggesting that Riyadh allowing Shia to take part in the Hajj to Mecca violates a Sura from the Quran: "O you who believe! Indeed the mushrikun are impure, so do not let them approach al-Masjid al-Haram after this year of theirs" [At-Tawbah: 28].

The irony seems lost on the group, however, that it was Saudi Arabia's execution of Sheikh Nimr al-Nimr in early 2016 which led to the latest inflammation of Shia/Sunni tensions, and that some Saudi clerics are some of the most overt propagators of hate speech towards Shia. ISIS pursues a dual strategy. It seizes on growing regional divisions taking place along increasingly religious lines, whilst accusing countries at the forefront of encouraging these divisions of "crafty politics with their neighbours."

ISIS has a long view of history, and its propaganda keenly portrays historical injustices as explanations of modern geopolitics. An article titled, "Know Your Enemy: Who Were the Safawiyyah," makes this dynamic clear, exploring the pertinence of the Safavids, a 16th to 18th Century Persian Shia theocracy, to contemporary regional affairs.

ISIS calls for the killing of Shia "leaders and laymen."

The persecution of Sunni Muslims under this regime, guided by a "Safawi-Rafidi political ideology" (another derogatory term for Shia), has "continued unsevered" to the current administration in Tehran, according to the magazine. ISIS says that Supreme Leader Ayatollah Khamenei and the Iranian regime take "guidance" from the Safavids, and "consider them the standard bearers of "good" governance." Adopting this line allows ISIS to portray conflict between Sunni and Shia as inevitable and deterministic.

Further, ISIS has often cited a so-called conspiracy between Jews and the Shia working to defeat the group and refers to them as "two sides of the same coin." Through a very obscure historic lens, ISIS alleges that Shia Islam from its very inception was instigated by a Jewish man named Ibn Saba', and that his actions were in the same vein as those of Saint Paul who "corrupted" the religion of Jesus. ISIS' claim that "[the Shia] will continue to wage war until they unite with the Jews" again shows their view that the conflict between Sunni and Shia is an inevitability. Escalation in sectarian rhetoric between Iran and Saudi Arabia only helps ISIS make this case in their propaganda.